The proposed effort presents development of a new biometric instrument Neuroskill to monitor fine neuromuscular performance. Through simple action of signing a signature or reproducing a cursive pattern, the device measures and records an individual's motor skill characteristics. Neuroskill uses an innovative approach for Correlation Function Analysis of behavioral signals. The method takes as its input precise measurements of handwriting dynamics ( accelerations and pressure) and returns values of criteria for stability, smoothness, and synchronization of handwriting motions. The device is an ordinary-size instrumental pen, with accompanying software, which is attached to a parallel port of a PC. The person can write on regular paper without restrictions for position of the person and the writing surface. The experimental study is focused on Parkinson's disease. Patients will be tested before taking their medication, and again forty minutes afterward. Additionally, patients will have assessment of pre-dose and post-dose Unified Parkinson's Disease Rating Scale (UPDRS). Neuroskill will provide medical experts with an objective quantitative evaluation of neuromuscular degradation, and will be very beneficial for both an early detection of the disease, and an effective monitoring of treatment in order to achieve the best balance of medications with minimal side effects. PROPOSED COMMERCIAL APPLICATION The instrument has a great potential for the following needs: early detection of motor impairment in at-risk populations; early diagnostics of neuromuscular illness (such as Parkinson's Disease); determination of patient response to treatment; monitoring of treatment effects over time; simple outpatient (e.g. home use) quantification of neurologic functions; development of neuromuscular targeted pharmaceuticals; expediting clinical trials of such pharmaceuticals. Neuroskill will be used by; a) Neurologists and other clinicians; b) Hospitals; c) Pharmaceutical companies; d) Medical research and educational institutes.